Illustrated Glossary of Organic Chemistry

Hofmann's rule: When an elimination reaction which can produce two or more alkene (or alkyne) products, the product containing the less highly substituted pi bond is major.

E2 elimination of 2-bromo-2-methylbutane with tert-butoxide follows Hofmann's rule, giving 2-methyl-1-butene (a disubstituted terminal alkene) as the major product.


E2 elimination of 2-bromo-2-methylbutane with methoxide follows Zaitsev's rule, giving 2-methyl-2-butene (a trisubstituted internal alkene) as the major product.